Vertebral implants and related methods of use

ABSTRACT

A vertebral insert may include a first linkage, a second linkage, and a third linkage. The first, second, and third linkages may at least partially defining a cavity. The insert may be movable between a collapsed configuration and an expanded configuration, and the movement of the first and second linkages with respect to one another may be configured to reciprocally move the insert between the collapsed and expanded configurations.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/185,884 which is a divisional application of U.S. application Ser.No. 14/466,640, filed Aug. 22, 2014, which is hereby incorporated byreference in its entirety for all purposes.

FIELD OF THE INVENTION

Various examples of the present disclosure relate generally to vertebralinserts, such as, e.g., fusion devices and related systems and methods.More specifically, the present disclosure relates to vertebral inserts,devices, systems, and methods for repairing and/or replacingintervertebral discs of a patient.

BACKGROUND

A common procedure for handling pain associated with intervertebraldiscs that have become degenerated due to various factors such as traumaor aging is the use of intervertebral spacers to fuse, e.g., one or moreadjacent vertebral bodies. Generally, to fuse the adjacent vertebralbodies, the native intervertebral disc is first partially or fullyremoved. An intervertebral spacer is then typically inserted betweenneighboring vertebrae to maintain normal disc spacing and restore spinalstability, thereby facilitating an intervertebral fusion.

There are a number of known conventional intervertebral spacers andmethodologies in the art for accomplishing the vertebral fusion. Theseinclude screw and rod arrangements, solid bone implants, andintervertebral spacers which include a cage or other implant mechanismwhich, typically, may be packed with bone and/or bone-growth inducingsubstances. These devices are implanted between adjacent vertebralbodies in order to fuse the vertebral bodies together, potentiallyalleviating any associated pain.

However, there are drawbacks associated with the known conventionalintervertebral spacers and methodologies. For example, some conventionalintervertebral spacers may lack sufficient surface area to optimallyfuse adjacent vertebral bodies.

SUMMARY OF THE DISCLOSURE

The present disclosure relates to examples of interbody vertebralinserts and related methods of use.

In one aspect, the present disclosure is directed to a vertebral insert.The vertebral insert may include a first linkage, a second linkage, anda third linkage. The first, second, and third linkages may at leastpartially defining a cavity. The insert may be movable between acollapsed configuration and an expanded configuration, and the movementof the first and second linkages with respect to one another may beconfigured to reciprocally move the insert between the collapsed andexpanded configurations.

In another aspect, the present disclosure is directed to a method ofinstalling an expandable vertebral insert. The method may includeinserting the vertebral insert between two vertebral bodies while thevertebral insert is in a collapsed configuration. The vertebral insertmay include a first linkage, a second linkage, and a third linkage. Thefirst, second, and third linkages may at least partially define acavity. The insert may be movable between a collapsed configuration andan expanded configuration. The movement of the first and second linkageswith respect to one another may be configured to reciprocally move theinsert between the collapsed and expanded configurations. The methodalso may include expanding the vertebral insert to an expandedconfiguration such that a cavity defined by the vertebral insert islarger in the expanded configuration than in the collapsedconfiguration.

In yet another aspect, the present disclosure is directed to a vertebralinsert. The vertebral insert may include a support member having asuperior surface, an inferior surface, a first groove disposed betweenthe superior surface and inferior surface on a first lateral side, asecond groove disposed between the superior surface and inferior surfaceon a second lateral side, and a first keel extending from one of thesuperior and inferior surfaces. The vertebral insert also may include afirst lateral spacer having a portion configured to extend within thefirst groove, and a second lateral spacer having a portion configured toextend within the second groove.

In yet another aspect, the present disclosure is directed to a vertebralspacer system. The system may include a vertebral spacer, and a bracketcoupled to the vertebral spacer. The system also may include a firstplate, and a second plate coupled to the first plate and the bracket.The second plate may be movable relative to the first plate, and thesecond plate may define a cavity through which the vertebral spacerextends.

In yet another aspect, the present disclosure is directed to a method oftreating a patient. The method may include attaching a first plate to afirst vertebral body, and attaching a second plate to a second vertebralbody. The first plate and the second plate may be coupled to oneanother. The method also may include moving the first and second platesaway from one another to distract the first and second vertebral bodies,and inserting a vertebral insert through a cavity defined by the secondplate.

In yet another aspect, the present disclosure is directed to a method oftreating a patient. The method may include inserting a vertebral insertinto the intervertebral space between two adjacent vertebral bodies, andexpanding the vertebral insert to distract the adjacent vertebralbodies. The method also may include inserting a spacer into theintervertebral space, and laterally coupling the spacer to the vertebralinsert after expanding the vertebral insert.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate various exemplary embodiments andtogether with the description, serve to explain the principles of thedisclosed embodiments.

FIG. 1 is a perspective view of a vertebral insert in accordance with anexample of the present disclosure.

FIG. 2 is a perspective view of a support member disposed betweenadjacent vertebral bodies in accordance with an example of the presentdisclosure.

FIGS. 3-9 depict an exemplary method of installing a vertebral insert inaccordance with an example of the present disclosure.

FIG. 10 is an exploded view of a vertebral insert in accordance with anexample of the present disclosure.

FIG. 11 is a top view of the vertebral insert of FIG. 10 with anendplate removed.

FIG. 12 is perspective view of a vertebral insert in accordance with anexample of the present disclosure.

FIGS. 13-16 depict an exemplary method of installing a vertebral insertin accordance with an example of the present disclosure.

FIGS. 17-20 depict a vertebral insert in accordance with an example ofthe present disclosure.

FIG. 21 is a perspective view of a spacer assembly in accordance with anexample of the present disclosure.

FIGS. 22-24 are perspective views of a plate assembly in accordance withan example of the present disclosure.

FIGS. 25-27 are perspective views of a bracket and spacer in accordancewith an example of the present disclosure.

FIGS. 28-36 depict an exemplary method of installing a spacer assemblyin accordance with an example of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to examples of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

A vertebral insert 100 shown in FIG. 1 may extend from a first end 102toward a second end 104, and include a support member 106, a firstlateral insert 108 and a second lateral insert 110. Support member 106,and first and second lateral inserts 108, 110 may be formed from arigid, bio-compatible material such as, e.g., titanium orpolyetheretherketone (PEEK), among others. Support member 106 and firstand second lateral inserts 108, 110 may be formed of the same ordifferent materials. In one example, support member 106 may be formedfrom titanium while first and second lateral inserts 108, 110 are formedfrom PEEK. Components that contact bone, including support member 106,and first and second lateral inserts 108, 110, may be treated with atitanium and/or hydroxyapatite plasma spray coating to encourage bonyon-growth, improving the strength and stability of the connectionbetween the respective component and the underlying bone (e.g., avertebral body). Any other suitable coating also may be provided on oneor more surfaces of support member 106, and first and second lateralinserts 108, 110. Such coatings may include therapeutic and/orantibiotic agents, if desired. Support member 106 and first and secondlateral inserts 108, 110 also may include radiopaque markings tofacilitate in vivo visualization and insertion.

Support member 106 may have an upper or superior surface 112 and a loweror inferior surface 113. In some examples, superior surface 112 andinferior surface 113 may be substantially parallel to one another, ormay have another suitable relationship to one another. In one example,superior surface 112 and/or inferior surface 113 may have asubstantially flat configuration. In some examples, superior surface 112and/or inferior surface 113 may have a variable cross-section, such as,e.g., bi-convex, e.g., curved from left to right and front to back, ormay have another suitable configuration. This curvature may givesuperior surface 112 and/or inferior surface 113 a partial dome orspherical shape. The curvature may be complementary to the naturalcurvature of an adjacent vertebral body and may provide for ananatomical fit between superior surface 112 and/or inferior surface 113with a vertebral body (shown in FIG. 2). Superior surface 112 andinferior surface 113 may be substantially similar to one another or mayhave different features. In one example, superior surface 112 andinferior surface 113 may be mirror images of one another. Superiorsurface 112 may be coupled to inferior surface 113 by a member 116.Superior surface 112, inferior surface 113, and member 116 may generallyform an I-beam type configuration defining a first groove 198 and asecond groove 199 (referring to FIG. 2). That is, a groove 198 may bedisposed between superior and inferior surfaces 112 and 113 at a firstlateral side of vertebral insert 100, and a groove 199 may be formedbetween superior and inferior surfaces 112 and 113 at a second lateralside of vertebral insert 100.

One or more keels 114 may be located on superior surface 112 and mayextend away from superior surface 112 at an angle. In one embodiment,the one or more keels 114 may include a plurality of serrations or othergeometric configurations. In the example shown in FIG. 1, keel 114 maybe formed at least partially from a substantially elongate member havingone or more notches 117 disposed on an axial end surface of keel 114.However, in some examples, a plurality of keels that are longitudinallyor laterally spaced from one another may extend away from superiorsurface 112. Once a discectomy has been completed, removing the damagednatural disc or damaged disc material, a groove or channel 180 (shown inFIG. 3) may be cut into the vertebral body to receive keel 114. Keel 114may be integrally formed with superior surface 112 or may alternativelybe attached to superior surface 112 by a suitable securing mechanism,e.g., an adhesive. Keel 114 may have one more holes, e.g., throughholes, or openings (not shown) perpendicular to the longitudinal axis ofthe keel. These holes or openings may provide an aperture for bonyin-growth, which may strengthen the connection or interface between theendplate and the vertebral body. In some examples, a plurality of keels114 may be arranged in a plurality of rows and/or columns, if desired,which can be inserted through a similarly arranged sequence of channelsor grooves formed in a vertebral body. Keels 114 may include suitablecoatings or other geometrical features (e.g., barbs or otherprotrusions) to promote bony in-growth/on-growth. In examples having aplurality of keels 114, each keel 114 may have varying lengths, widths,and/or other dimensions. One or more keels 115 (which may include one ormore of the aforementioned features of keels 114) may be located oninferior surface 113 and may extend away from inferior surface 113 at anangle.

Keel 114 may include a ramp 120 at the second, leading end 104 ofvertebral insert 100. Superior surface 112 may include two inclinededges directed laterally inward toward a first longitudinal axis A atsecond, leading end 104. Longitudinal axis A may extend longitudinallythrough the longitudinal midsection of superior surface 112. A firstinclined edge 130 of superior surface 112 may incline from a firstlateral side of vertebral insert 100 toward longitudinal axis A, while asecond inclined edge 132 of superior surface 112 may incline from asecond lateral side of vertebral insert 100 toward longitudinal axis A.Ramp 120 and inclined edges 130 and 132 may generally converge at apoint 134 disposed along longitudinal axis A. Keel 115 may include aramp 136 (shown only in FIG. 3) that may include one or more features oframp 120 of keel 114. Inferior surface 113 may include a first inclinededge (not shown) and a second inclined edge 138 that may include one ormore of the features of first and second inclined edges 130 and 132 ofsuperior surface 112. The first inclined edge and second inclined edge138 of keel 115 may converge toward a second longitudinal axis B.Longitudinal axis B may extend longitudinally through the longitudinalmidsection of inferior surface 113. The first inclined edge and secondinclined edge 138 of inferior surface 113 and ramp 136 of keel 115 maygenerally converge at a point 139 that is disposed along longitudinalaxis B.

The bladed or wedged formation of second, leading end 104 of vertebralinsert 100 may form the leading insertion end of vertebral insert 100(e.g., the end that enters the intervertebral space first). The bladedor wedged formations may possess a mechanical advantage over otherconfigurations. More specifically, the bladed or wedged formations mayreduce the amount of force required to insert vertebral insert 100 intoa patient. Further, in some examples, the portion of support member 106at first end 102 may be the trailing end of support member 106 (e.g.,the end that enters the patient second or last). The trailing end ofsupport member 106 may be inserted between vertebral bodies by anysuitable mechanism including, e.g., hammering, sliding, pushing, orother mechanisms.

First lateral spacer 108 may include an elongate member 163 that extendsfrom a first, trailing end 160 toward a second, leading end 162. In someexamples, elongate member 163 may be generally cuboid, although othersuitable configurations, e.g., cylindrical or the like, are alsocontemplated. Elongate member 163 may cooperate with groove 198 or 199to couple support member 106 with first lateral spacer 108. That is,elongate member 163 and groove 198 or 199 may form, e.g., a tongue andgroove joint, although other suitable joints and mating relationshipsare also contemplated. A generally ellipsoid (or otherwise elongated)ring 165 may be partially defined by flange portions 170 and 172, andmay extend from elongate member 163. The ellipsoid ring 165 may at leastpartially define the outer perimeter of a cavity 167. Cavity 167 mayhave a generally ellipsoidal (or otherwise elongated) cylindrical shape,although other suitable configurations are also contemplated. In someexamples, the outer curvature of ellipsoid ring 165 may be determined bythe posterior curvature of the vertebral bodies between which vertebralinsert 100 is implanted.

Cavity 167 may be filled with bone graft or similar bone-growth inducingmaterial to further promote and facilitate the intervertebral fusion.Cavity 167, in one example, may be packed with bone graft or similarbone-growth inducing material to promote the growth of bone through andaround the vertebral insert. Such bone graft may be packed into cavity167, subsequent to, or during implantation of the vertebral insert 100.

Second lateral spacer 110 may include an elongate member 143 thatextends from a first, trailing end 140 toward a second, leading end 142(referring to FIG. 4). In some examples, elongate member 143 may begenerally cuboid, although other suitable configurations, e.g.,cylindrical, are also contemplated. Elongate member 143 may cooperatewith groove 198 or 199 to couple support member 106 with second lateralspacer 110. That is, elongate member 143 and groove 198 or 199 may form,e.g., a tongue and groove joint, although other suitable joints andmating relationships are also contemplated. Flange portions 144, 146,and 148 may extend away from a lateral end surface of elongate member143 in the superior and inferior directions forming a generally t-shapedcross section with elongate member 143. In some examples, flangeportions 144, 146, and 148 may mate and/or cooperate with lateral endsurfaces of superior surface 112 and inferior surface 113, respectively.A groove 150 may be disposed longitudinally between flange portions 144and 146, while a groove 152 may be disposed between flange portions 146and 148. It should be noted that while two grooves and three flanges areshown in some examples, any other suitable number of grooves and flangesalternatively may be utilized to improve graft area, and/or ease ofmachining, among other factors. An arc portion 154 may extend laterallyoutward between first end 140 and second end 142. Arc portion 154,flanges 144, 146, and 148, and grooves 150 and 152 may define a cavity156. In some examples, flanges 144, 146, 148, and arc portion 154 maydefine a generally D-shaped ring. It should be noted that, in someexamples, the curvature of arc portion 154 may approximate the anteriorcurvature of adjacent vertebral bodies between which vertebral insert100 is inserted. Cavity 156 may be filled with bone graft or otherbone-growth inducing material in a substantially similar manner asdescribed with respect to cavity 167.

In some examples, vertebral insert 100 may be delivered by a minimallyinvasive (MIS) lateral lumbar interbody fusion (LLIF) approach.Vertebral insert 100 may be configured to provide increased surface areaover conventional vertebral inserts. Vertebral insert 100 may beself-distracting with the insertion of keels 114, 115, and may decreasethe chance of subsidence. In some examples, vertebral insert 100 may notneed additional fixation such as, e.g., plates or other locking systemsbecause keels 114 and 115 may prevent vertebral insert 100 from backingout of the intervertebral space. That is, vertebral insert 100 may be astandalone implant. Vertebral insert 100 may provide improved spacer fitby allowing for anterior and posterior spacer selection. In someexamples, vertebral insert 100 may provide increased total surface areacontact with vertebral bodies while also engaging harder bone around theapophyseal ring. In still further examples, vertebral insert 100 mayprovide for increased amount of bone graft or bone-growth inducingsubstances to be utilized over conventional devices.

FIGS. 3-9 illustrate an exemplary installation sequence for vertebralinsert 100. Initially, a groove 180 may be formed through the superiorsurface of a vertebral body 2. A groove 182 (shown only in FIG. 9) alsomay be formed in the inferior surface of vertebral body 4. Keels 115 and114 of support 106 then may be aligned with grooves 180 and 182,respectively. Support 106 then may be inserted between vertebral bodies2 and 4 by a suitable mechanism to place keels 115 and 114 into thegrooves formed in the vertebral bodies, and to place superior andinferior surfaces 112 and 113 into the intervertebral space. Oncesupport 106 is secured between vertebral bodies 2 and 4, one or morelateral inserts (e.g., first and second lateral inserts 108, 110) may bealigned with one or more grooves 198, 199 of support 106 and insertedbetween vertebral bodies 2 and 4. It should be noted that any suitablelateral insert may be selected to mate with support 106. Thus, the useof support 106 may permit operator flexibility and discretion wheninstalling vertebral insert 100. For example, one or both of first andsecond lateral spacers 108, 110 may include modifications to, e.g.,outer curvature, height, lordosis correction, or other featuresdepending on the specific geometry of vertebral bodies 2 and 4. In someexamples, lateral spacers 108 and 110 may provide for a continuousamount of lordotic correction, or alternatively, may each be configuredto provide a different amount of lordotic correction to various portionsof the vertebral bodies. In some examples, vertebral insert 100 mayprovide a higher amount of height and lordotic correction by havingseparate anterior and posterior spacers. In some examples, vertebralinsert 100 may allow for evenly distributed weight loads. Lateralspacers 108 and 110 may be secured between vertebral bodies 2 and 4 byany suitable mechanism. In one example, rotatable locking flanges orscrews (not shown) may be disposed at the trailing end of support 106.After lateral spacers 108 and 110 are inserted between the vertebralbodies 2 and 4, the locking flanges or screws may be rotated into alocking position to prevent spacers 108 and 110 from backing out of theintervertebral space.

FIGS. 10 and 11 show different views of a vertebral insert 200, inaccordance with a further aspect of the present disclosure. Thevertebral insert 200 may include a body portion 202, a first endplate204, a second endplate 206, a translation member 208, and an actuationmember 210. Translation member 208 and actuation member 210 maycooperate to axially (e.g., vertically) move endplates 204 and 206 awayfrom one another, thereby increasing the axial height of vertebralinsert 200. The first endplate 204 can include a pair of openings 212and 214 through which bone graft material can be received or deposited.Likewise, the second endplate 206 can have one or more similar openings.In addition to these features, the vertebral insert 200 may include aninterference nut 216 that is operably attached to a rear section (e.g.,a trailing end) of the body portion 202, as well as a pair ofstabilization members 218, 220. In some examples, endplates 204 and 206may be formed of PEEK or another suitable material.

FIG. 10 illustrates an exploded view of a vertebral insert 200, whileFIG. 11 shows a top view of the same device with a first endplate 204removed. As shown in both views, a translation member 208 may include atleast three expansion portions 222, 224, and 226, which may be connectedvia bridge portions 227. The expansion portions 222, 224, and 226 eachmay have angled surfaces that are configured to engage grooved portionsof the first and second endplates 204 and 206. In some examples, theangled surfaces may be of similar angles, while in other examples, theangled surfaces may be of different angles. In at least some examples,providing at least three expansion portions 222, 224 and 226 may allowfor an even expansion along a majority of the length of the body portion202 of the vertebral insert 200.

The translation member 208 may be received in the central opening of thebody portion 202. The body portion 202 may include a first end 228 and asecond end 230. In some examples, the first end 228 may include one ormore apertures 232, 234 as shown in FIGS. 10 and 11. These apertures232, 234 may receive one or more stabilization members 218, 220.

In some examples, the stabilization members 218, 220 each may include afirst substantially smooth portion 236, 238, respectively, and a secondthreaded portion 240, 242, respectively. The stabilization members 218,220 may be inserted through the apertures 232, 234 of the body portion202, with the threaded portions 240, 242 serving as the leading end thatenters the apertures. After passing through the apertures 232, 234 ofthe body portion 202, the stabilization members 218, 220 may come intocontact with a side of the translation member 208. In some examples, thethreaded portions 240, 242 of the stabilization members 218, 220 may bethreaded into mateable threaded surfaces of the translation member 208.In some examples, by using a pair of stabilization members 218, 220 asshown in FIGS. 10 and 11 on a first end of the body portion 202, rockingof the body portion 202 during expansion and contraction of the device10 may be prevented.

While the illustrated example in FIGS. 10 and 11 show a pair ofstabilization members 218, 220, in other examples, a singlestabilization member or more than two stabilization members can be usedto assist in preventing rocking of the body portion 202. In addition,while the stabilization members 218, 220 are illustrated as having asubstantially cylindrical surface section, in other examples, thestabilization members 218, 220 can include other shapes and geometries.For example, in other examples, the stabilization members 218, 220 canhave a surface that includes at least one edge or corner.

As shown in FIGS. 10 and 11, the body portion 202 also may includeinterference nut 216 that is positioned within a rear section of thebody portion 202. In some examples, the interference nut 216 may beseparate and removable from the body portion 202, while in otherexamples, the interference nut 216 may not be removable from the bodyportion 202. In some examples, the interference nut 216 may include asquare nut that is operably connected to a rear section of the bodyportion 202. The interference nut 216 can be mateably connected to arear of the body portion 202, for example, via a dove-tail type cut thatencapsulates the interference nut 216. The interference nut 216 can beadvantageously formed of a biocompatible material. In some examples, theinterference nut 216 may be formed of PEEK.

The interference nut 216 can include a hole (not shown) that is capableof receiving the actuation member 210 therethrough. The actuation member210, which can comprise a threaded set screw, may pass through theinterference nut 216 and into contact with the translation member 208,as best shown in FIG. 11. The interference nut 216 may serve to add dragto the actuation member 210 as it passes therethrough, therebyestablishing an interference fit. By providing an interference fit, therisk of the actuation member 210 being loosened prior to or during usemay be minimized.

A vertebral insert 300 is shown in FIG. 12 that may be substantiallysimilar to vertebral insert 200 except that a body portion 302 may beutilized instead of body portion 202. Vertebral insert 300 may includefirst and second endplates 304 and 306 that may include one or morefeatures of first and second endplates 204 and 206 of vertebral insert200. Body portion 302 may be substantially similar to body portion 202except that an elongate member 308 may extend from a longitudinal sidesurface 310 of body portion 302. Elongate member 308 may generally havea T-shaped cross section that extends along a portion of longitudinalside surface 310, although other suitable configurations are alsocontemplated. A stabilization aperture 312 may be disposed at a middleportion of elongate member 308. Stabilization aperture 312 may beconfigured to receive a threaded portion of a stabilization member (notshown) to couple body portion 302 to a translation member (not shown,but similar to translation member 208 described with reference to FIG.11). Thus, stabilization aperture 312, in at least some examples, mayhelp to provide rotational stability to the translation member relativeto the body portion 302 prior to or during use of the vertebral insert300.

Once vertebral insert 300 is installed between vertebral bodies as shownin FIGS. 13 and 14, the superior-inferior height (e.g., the distancebetween endplates 304 and 306) may be increased. When vertebral insert300 is moved to the expanded height, a lateral spacer 340 also may beinserted between vertebral bodies 2 and 4. In other examples, lateralspacer 340 may be inserted into the intervertebral space and coupled tovertebral insert 300 before the height of vertebral insert 300 isincreased. Lateral spacer 340 may be configured to mate with vertebralinsert 300. Lateral spacer 340 may extend from a first, trailing end 342toward a second, leading end 344. Lateral spacer 340 may include agroove or channel 346 configured to mate with elongate member 308 ofbody portion 302. Channel 346 may be at least partially defined by oneor more rails 348. The ends of channel 346 and rails 348 may terminateat a gap 369 which extends in the superior-inferior directions. Gap 369may facilitate machining of lateral spacer 340 and may increase theamount of graft that can be applied to vertebral insert 300. In someexamples, any additional number of gaps 369 may be included along thelength of channel 346 and rails 348. That is, channel 346 and rails 348may include a series of interrupted channels and rails that throughwhich elongate member 308 of body portion 302 may pass through. In someexamples, elongate member 308, channel 346, and rails 348 may form atongue and groove joint, although other suitable connections are alsocontemplated. Gap 369 may be configured to separate channel 346 andrails 348 from a stop surface 364 that is configured to abut elongatemember 308 of vertebral insert 300. In some examples, lateral spacer 340may define a cavity 350 that may be similar to cavities 150 and 167described above. Cavity 350 may be packed with bone graft or bone-growthinducing substances in a substantially similar manner as cavities 150and 167. In some examples, cavity 350 may be at least partially definedby an arc portion 352 that may approximate the anterior curvature of avertebral body. However, any or all portions of vertebral insert 300 canbe formed in any other suitable configuration depending upon thegeometry of the vertebral bodies between which it is to be inserted.

In one example, body portion 302 may be positioned at the posterior endbetween two vertebral bodies. However, it is also contemplated that bodyportion 302 also may be positioned toward the anterior end. Then,lateral spacer 340 may be inserted at the anterior end (if body portion302 is positioned at the posterior end) or the posterior end (if bodyportion 302 is positioned at the anterior end). It is also contemplatedthat body portion 302 may include an additional elongate member 308 at alongitudinal side surface opposite of longitudinal side surface 310 toallow body portion 302 to mate with two different lateral spacers. Forexample, in some examples, body portion 302 may accommodate anadditional lateral spacer, e.g., as shown in FIGS. 1-9. FIG. 15 shows atop view of vertebral insert 300 and lateral spacer 340 installed on avertebral body. FIG. 16 is a side view of vertebral insert 300 andlateral spacer 340 installed between vertebral bodies. In some examples,one or more of vertebral insert 300 and lateral spacer 340 may beconfigured to provide lordosis correction. In some examples, vertebralinsert 300 and lateral spacer 340 together may form a continuous angledand ramped surface. In other examples, vertebral insert 300 and lateralspacer 340 each may be ramped at different angles to provide differingdegrees of lordosis correction based on the specific geometries ofvertebral bodies between which they are inserted.

In some examples, vertebral insert 300 and lateral spacer 340 may besecured between vertebral bodies 2 and 4 via a minimally invasive platesystem that is configured to provide stabilization through a lateralapproach. The plate system may include brackets, bone screws, blockingscrews, and other suitable elements to maintain vertebral insert 300 andlateral spacer 340 between vertebral bodies 2 and 4.

In some examples, vertebral insert 300 and lateral spacer 340 may bedelivered by a minimally invasive (MIS) lateral lumbar interbody fusion(LLIF) approach. Vertebral insert 300 and lateral spacer 340 may beconfigured to provide increased surface area over conventional vertebralinserts. Vertebral insert 300 may provide improved spacer fit byallowing for anterior and/or posterior spacer selection. In someexamples, vertebral insert 300 and lateral spacer 340 may provideincreased total surface area contact with vertebral bodies while alsoengaging harder bone around the apophyseal ring. In still furtherexamples, vertebral insert 300 and lateral spacer 340 may provide forincreased amount of bone graft or bone-growth inducing substances to beutilized over conventional devices. In some examples, vertebral insert300 may provide for more even weight load distribution, reduce cagesubsidence, provide a large fusion bed graft area, and/or a higherdegree of height and lordotic correction by having separate posteriorand/or anterior spacers.

Another example of a vertebral insert 400 is shown in FIGS. 17-20.Vertebral insert 400 may be reciprocally movable between a first,collapsed configuration (shown in FIG. 17) and a second, expandedconfiguration (shown in FIG. 18). In some examples, vertebral insert 400may be a collapsible and expandable ring-shaped member that defines acavity 460. Cavity 460 may be packed with bone graft in a substantiallysimilar manner as set forth above. Vertebral insert 400 may extend froma first, trailing end 402 toward a second, leading end 404. Vertebralinsert 400 may include a first linkage 406, a second linkage 408, athird linkage 410, and a fourth linkage 412.

First linkage 406 may include a hollow elongate portion 414 and a flangeportion 416. Hollow elongate portion 414 may be generally cylindrical orhave another suitable shape. Flange portion 416 may extend radiallyoutward from hollow elongate portion 414 at a middle longitudinalsection or other suitable longitudinal section. An elongate member 418(e.g., a rod) may extend from flange portion 416 to couple first linkage406 with second linkage 408. Elongate member 418 also may prevent therotation of first linkage 406 relative to second linkage 408. In analternative example, hollow elongate portion 414 may be formed in ashape configured to prevent the relative rotation of the first andsecond linkages 406 and 408 (such as, e.g., square, rectangular, star,or the like). Flange portion 416 also may include features 417 to couplefirst linkage 406 to third linkage 410. Features 417 may include a pairof flanges configured to form a joint with an extension of third linkage410 (e.g., a bridle joint, a mortise and tenon joint, or anothersuitable joint or connection). In some examples, the pair of flanges mayhave apertures or pin holes that are aligned with one another to receivea securing mechanism such as, e.g., a pin that extends through each ofthe pair of flanges and the extension of third linkage 410, so as torotatably couple first linkage 406 with third linkage 410.

Second linkage 408 may include an end portion 420 having a recess 422(referring to FIG. 18) disposed therethrough that is configured toslidably receive hollow elongate portion 414 of first linkage 406. Alongitudinal portion 424 may extend from end portion 420 toward adistraction end 426. End portion 420 may be disposed at an angle (e.g.,90 degrees) relative to longitudinal portion 424. A recess 427 (shown indotted lines in FIG. 17) may extend through end portion 420 and at leastpartially through longitudinal portion 424 to receive elongate member418 therein. Distraction end 426 may be disposed at second, leading end404 of vertebral insert 400 and may be wedged, bladed, or have anothersuitable shape to facilitate the distraction of a pair of vertebralbodies upon insertion of vertebral insert 400. That is to say,distraction end 426 may include a tapered configuration. In someexamples, because of the relationship of recess 422 and elongate portion414, and of elongate member 418 and recess 427, first linkage 406 andsecond linkage 408 may be configured to slidably and longitudinally movewith respect to one another.

Third linkage 410 may be a generally elbow shaped member that may becoupled to first linkage 406 (via features 417 described above) at oneend, and coupled to fourth linkage 412 at a second end. Third linkage410 may be formed from two arms 428 that converge at a bend 430 joiningthe two arms 428. In some examples, the two arms 428 may form an obliqueangle with respect to one another. The second end of third linkage 410may include mating features 432 that may be substantially similar tomating features 417 of first linkage 406. The mating features 432 may beconfigured to receive an extension of fourth linkage 412 to form a jointsuch as, e.g., a bridle type joint, a mortise and tenon type joint, oranother suitable joint or connection.

Fourth linkage 412 also may be a generally elbow shaped member that iscoupled to third linkage 410 at one end, and coupled to second linkage408 at another end. Each end of fourth linkage 412 may include anysuitable connector, extension, flange, coupling, or the like to matewith a corresponding feature on third linkage 410 and/or second linkage408. Third and fourth linkages 410 and 412 together, when vertebralinsert 400 is in the expanded configuration, may form an arc portionthat generally approximates the anterior curvature of a vertebral body.In the collapsed configuration of vertebral insert 400, third and fourthlinkages 410 and 412 may be buckled laterally inward. In the expandedconfiguration of vertebral insert 400, third and fourth linkages 410 and412 may bow laterally outward. In some examples, the superior-inferiorheight of vertebral insert 400 may remain unchanged in both thecollapsed and expanded configuration of vertebral insert 400.

The various linkages described with reference to FIG. 17 may be formedof any suitable biocompatible material, such as, e.g., titanium, PEEK,or the like. In some examples, the linkages may be treated with atitanium and/or hydroxyapatite plasma spray coating to encourage bonyon-growth, improving the strength and stability of the connectionbetween the respective component and the underlying bone (e.g., avertebral body).

Vertebral insert 400 may be inserted between vertebral bodies while in acollapsed configuration (shown in FIG. 17) while attached to apositioning tool 490, to another suitable tool, or unattached to a tool.A holding member 492 may be disposed at a distal end of positioning tool490 and may extend through hollow elongate portion 414 and end portion420 to couple to a recess or bore (not shown) disposed withindistraction end 426 of second linkage 408. In one example, holdingmember 492 may be a threaded screw extending from a proximal portion484. Holding member 492 may be fastened to distraction end 426 in someexamples. An elongate drive member 496 may be slidable relative toholding member 492. In some embodiments, elongate drive member 496 maybe hollow. Once holding member 492 is fastened to distraction end 426 ofsecond linkage 408, driving member 496 then may be coupled to a firstend of first linkage 406 as shown in FIG. 17 (via, e.g., threads or thelike). Drive member 496 may be advanced distally to push first linkage406 from first end 402 toward second end 404 of vertebral insert 400,causing vertebral insert 400 to move from the first, collapsedconfiguration to the second, expanded configuration (FIG. 18). Oncevertebral insert 400 is in the expanded configuration, a suitablelocking mechanism such as, e.g., a tang, blocking screw, latch, or othersuitable locking mechanism may stabilize vertebral insert 400 into theexpanded configuration. Once locked into the expanded configuration,holding member 492 and drive member 496 may be disconnected andwithdrawn from the patient. In some examples, a distal portion ofholding member 492 may be left within vertebral insert 400 and onlyproximal portion 494 and drive member 496 may be withdrawn. Thus, insome examples, holding member 492 may be configured to lock vertebralinsert into the expanded configuration, via, e.g., a rotatable lockingflange (not shown) disposed at a proximal end of holding member 492.Subsequently, bone graft may be packed into cavity 460 via, e.g., alumen of elongate drive member 496.

A spacer assembly 500 is shown in FIGS. 21-36. Spacer assembly 500 mayinclude a plate assembly 600, one or more fastening members 502, abracket 800, and a spacer 802. As best seen in FIGS. 22 and 23, plateassembly 600 may extend from a first end 602 toward a second 604. Insome embodiments, plate assembly 600 may include a plurality of platesmovable relative to each other, as described below. For example, a firstplate 606 may extend from first end 602 toward second end 604, while asecond plate 608 may extend from second end 604 toward first end 602. Inembodiments having a single plate (not shown), however, a cavityextending through plate assembly 600 may be selectively adjustable.

With specific reference to FIGS. 22-24, first plate 606 may include asubstantially rectangular portion 610 and a substantially semi-circularportion 612 extending from rectangular portion 610. As shown in FIG. 22,first plate 606 may further include a throughbore 614. Throughbore 614may be disposed completely in semi-circular portion 612, completely inrectangular portion 610, or partially in semi-circular portion 612 andpartially in rectangular portion 610, as shown. On a first side 616 offirst plate 606, throughbore 614 may include an opening 618. Opening 618may be surrounded by a raised lip 620 extending around the periphery ofopening 618. Raised lip 620 may include any suitable configuration. Inone embodiment, raised lip 620 may include a substantially squarecross-sectional configuration. Those of ordinary skill in the art,however, will recognize that raised lip 620 may include any suitablecross-sectional configuration. Though the depicted embodiment showsraised lip 620 as continuously extending around opening 618, raised lip620 may include one or more breaks, such that it does not extendcontinuously around opening 618. In some embodiments, opening 618 mayfurther include a radially inward lip 622 extending away from a walldefining opening 618.

With continued reference to FIG. 22, first side 616 may further includea stepped portion 624. Stepped portion 624 may be spaced from a surface626 by a vertical wall 628 (shown in FIG. 24). Stepped portion 624 mayinclude any suitable configuration. In one embodiment, stepped portion624 may include a substantially constant cross-sectional dimension.However, in some embodiments, stepped portion 624 may include a taperedcross-sectional configuration. Stepped portion 624 may have a smallercross-sectional dimension (e.g., thickness) relative to a remainder offirst plate 606. Stepped portion 624 may include a surface on first side616 having one or more geometric configurations 630 to increasefriction. For example, geometric configurations 630 may include one ormore teeth, ridges, divots, cavities, or other similar structures.Further, stepped portion 624 may define an elongated channel 632extending through stepped portion 624. Although a single elongatechannel 632 is depicted, stepped portion 624 may include a plurality ofchannels or cavities. Elongate channel 632 may include any suitableconfiguration. As will be described in further detail below, elongatechannel 632 may be configured to receive a portion of a locking member634.

With reference now to FIG. 23, first plate 606 may include a second side636 disposed opposite to the first side 616. Second side 636 may besubstantially planar. In some embodiments, an opening 638 of throughbore614 may be surrounded by a raised atraumatic lip 640. Lip 640 mayinclude any suitable configuration, including, but not limited to, acurved outer periphery. A portion of lip 640 may include a cutout 642corresponding to an end of elongate channel 632. As can also be seen inFIG. 23, elongate channel 632 may extend through first plate 606 to anopening 644 on second side 636. Opening 644 may include counterborefeatures extending around a periphery of opening 644 to receive an endof a locking member 634.

With continued reference to FIGS. 22-24, second plate 608 may include asubstantially rectangular portion 650 and a substantially semi-circularportion 652 extending from rectangular portion 650. Second plate 608 mayfurther include a throughbore 654. Throughbore 654 may be disposedcompletely in semi-circular portion 652, completely in rectangularportion 650, or partially in semi-circular portion 2215 and partially inrectangular portion 650, as shown. On a first side 656 of second plate608, throughbore 654 may include an opening 658. Opening 658 may besurrounded by a raised lip 660 extending around the periphery of opening658. Raised lip 660 may include any of the features described above withrespect to raised lip 620. In some embodiments, opening 658 may furtherinclude a radially inward lip 662 extending away from a wall definingopening 658.

In the embodiment shown in FIGS. 22-24, rectangular portion 650 maydefine a cavity 664 (e.g., a rectangular cavity configured to receive avertebral spacer 802 shown in FIGS. 25-27). Locking member 634 mayextend through a recess disposed in an end wall 666 that at leastpartially defines cavity 664. The end wall 636 may include a protrustion668 that extends into cavity 664. The protrustion 668 may accommodatevarious features (e.g., locking features) associated with locking member634. In some examples, locking member 634 may include a head portion 670that abuts the first side 656 of second plate 608. Cavity 664 also maybe at least partially defined by a side wall 672 and side wall 674. Insome examples, side walls 672 and 674 may be substantially parallel toone another and orthogonal to end wall 636. A locking member 676 mayextend through a recess disposed in side wall 672 while a locking member678 may extend through a recess disposed in side wall 674. Lockingmembers 676 and 678 may include one or more locking features describedwith reference to locking member 634. Side wall 672 may include aprotrusion 680 and side wall 674 may include a protrusion 682.Protrusions 680 and 682 may accommodate locking features of lockingmembers 676 and 678, respectively, and may be configured to extend awayfrom cavity 664 in opposite directions.

With reference now to FIG. 23, second plate 608 may include a secondside 686 disposed opposite to the first side 656. Second side 686 may besubstantially planar. In some embodiments, an opening 688 of throughbore654 may be surrounded by a raised atraumatic lip 690. Lip 690 mayinclude may include one or more features described above with referenceto lip 640. Second side 686 may further include a stepped portion 694disposed on end wall 674. Stepped portion 694 may be spaced from asurface 696 by a vertical wall 698 (shown in FIG. 23). Stepped portion694 may include any suitable configuration including those describedwith reference to stepped portion 624 of first plate 606, and mayinclude geometric features 700 that may be substantially similar togeometric features 630. Second side 686 also may include a steppedportion 704 that is disposed along end wall 672. Stepped portion 704 maybe spaced from surface 696 by a vertical wall 708 and may includegeometric features 710 that are substantially similar to geometricfeatures 630 and 700. The stepped portions of second plate 608 (e.g.,stepped portions 694, 704 and a stepped portion of end wall 666) mayhave a smaller cross-sectional dimension (e.g., thickness) than aremainder of second plate 608. Side walls 672 and 674 also may includecounterbore features 712 and 714 that may be configured to receiveportions of locking members 676 and 678, respectively.

As described above, first and second plates 606 and 608 may be movablerelative to one another when coupled via locking member 634. In someexamples, stepped portion 624 of first plate 606 may be slidably coupledto stepped portions 694 and 704 of second plate 608. When coupled to oneanother, first and second plates 606 and 608 may form an adjustablejoint or other suitable connection. In one example, first and secondplates 606 and 608 may form a half lap splice joint, although othersuitable connections are also contemplated.

The relative movement of first plate 606 and 608 with respect to oneanother may define an effective opening of cavity 664. That is, cavity664 may be movable between a first, fully-open configuration (shown inFIG. 24), and a second, partially-open configuration (shown in FIG. 22).In the second, partially-open configuration, stepped portion 624 offirst plate 606 may extend over and cover cavity 664, reducing theeffective opening size of cavity 664. That is, stepped portion 624 mayextend over cavity 664 to reduce the size of a vertebral spacer that canbe received by cavity 664. It is also contemplated that cavity 664 mayinclude any number of intermediate configurations between the first,fully-open configuration and the second, partially-open configuration.

Locking member 634 may be reciprocally movable between a plurality ofconfigurations and may be configured to couple first and second plates606 and 608 to one another. In a first configuration, locking member 634may couple first plate 606 to second plate 608 and may permit therelative movement of first and second plates 606 and 608 with respect toone another. In a second configuration, locking member 634 may fix theorientation of first plate 606 with respect to second plate 608 by anysuitable mechanism such as, e.g., tightening a threaded engagement,moving a locking flange or other mechanism into a locking position, orthe like.

FIGS. 25-27 depict exploded and assembled views of a bracket 800 and aspacer 802. Bracket 800 may be a bracket configured to couple to bothspacer 802 and plate assembly 600 described above. Bracket 800 mayinclude a generally rectangular elongate surface 804 having a firstelongate cavity 806 and a second elongate cavity 810 extending throughelongate surface 804. The lengths of elongate cavities 806 and 810 maybe generally parallel to one another, and each may be generallyperpendicular to the length of elongate surface 804, although othersuitable configurations are also contemplated. Bracket 800 also mayinclude a protrusion 812 (shown only in FIG. 26) that extends away fromelongate surface 804. A bore 814 may extend through elongate surface 804and protrusion 812 to receive a fastener (e.g., a threaded screw or thelike). In some examples, bracket 800 may be curved at its lateral edges.

Spacer 802 may be any suitable intervertebral spacer. In the exampleshown in FIGS. 25-27, spacer 802 may be a generally rectangular spacerdefining a cavity 816. Cavity 816 may be packed with bone graft orbone-growth inducing materials. A lateral end surface of spacer 802 maydefine a recess 818 and a bore 820 configured to receive protrusion 812and fastener 822 respectively. Recess 818 and bore 820 of spacer 802 maybe complimentary to protrusion 812 and fastener 822 so as to limitmovement of bracket 800 and spacer 802 with respect to one another.Spacer 802 may be any suitable intervertebral spacer, and may includeone or more of inferior surfaces, superior surfaces, biconvex surfaces,among others. In some examples, the surfaces of spacer 802 or any otherbone contacting surface described in the present disclosure may includeone or more of teeth, ridges, friction increasing elements, keels, orgripping or purchasing projections.

FIGS. 28-36 depict an exemplary method of installing spacer assembly 500within a patient. Initially, plate assembly 600 may be brought inproximity with two vertebral bodies 2 and 4 (FIG. 28). In one example,during initial installation, first and second plates 606 and 608 may bein the second, partially-open configuration where cavity 628 has itssmallest effective opening. As shown in FIG. 29, bore 654 may be alignedwith vertebral body 4 while, bore 614 may be aligned with vertebral body2. First and second plates 606 and 608 may be moved toward thefully-opened configuration depending upon the desired distance betweenvertebral bodies 2 and 4 to optimize fit. It is contemplated that insome examples, plate assembly 600 may be in an intermediateconfiguration between the first and second configurations at this stagesuch that cavity 664 is at an intermediate opening size. A fasteningmember 502 may then be used to secure one of first or second plates 606and 608 to a respective vertebral body (FIG. 30), and another fasteningmember 502 may be used to secure another fastener 502 to secure theother of first and second plates 606 and 608 to a respective vertebralbody (FIG. 31).

Once first and second plates 606 and 608 are secured to vertebral bodies2 and 4, an operator may distract vertebral bodies 2 and 4 from oneanother via first and second plates 606 and 608. That is, an operatormay move first and second plates 606 and 608 away from one another tomove vertebral bodies 2 and 4 away from one another. Once vertebralbodies 2 and 4 have been moved away from one another (e.g., distracted)by a sufficient distance, an operator may lock the distracted positionby moving locking member 634 from an unlocked configuration to a lockedconfiguration, thereby locking the positions of first and second plates606 and 608 and also vertebral bodies 2 and 4. It is furthercontemplated that the positions of first and second plates 606 and 608may be fixed with respect to one another by any other suitablemechanism.

Once vertebral bodies 2 and 4 are distracted and locked into position,spacer 802 may be inserted through cavity 664 (FIGS. 34 and 35). Asspacer 802 is moved between the vertebral bodies, bracket 800 may abutsecond plate 608 of plate assembly 600. Further, locking elements 676and 678 may be positioned to extend through elongate cavities 806 and810. The locking elements 676 and 678 may then be moved from aninsertion configuration to a locking configuration, thereby securingspacer 802 between vertebral bodies 2 and 4.

Spacer assembly 500 may provide one or more of the following advantages,including: an increased tactile feel while distracting, an increasedrange of distraction height, increased bone graft size and placement,improved radiolucent viewing, decreased stress on endplates and reducedchance of subsidence, and the potential elimination of the need forposterior fixation.

Any aspect set forth in any example may be used with any other exampleset forth herein. Every device and apparatus set forth herein may beused in a suitable medical procedure, such as, e.g., a vertebral discreplacement procedure, and may be advanced through any suitable bodylumen and body cavity.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the disclosed systems andprocesses without departing from the scope of the disclosure. Otherexamples of the disclosure will be apparent to those skilled in the artfrom consideration of the specification and practice of the embodimentsdisclosed herein. It is intended that the specification and examples beconsidered as exemplary only.

We claim:
 1. A vertebral spacer system, comprising: a vertebral spacerhaving a body portion, a first endplate, a second endplate, atranslation member, and an actuation member, wherein the translationmember and the actuation member cooperate to move the first and secondendplates away from one another, thereby increasing the height of thevertebral spacer; wherein the vertebral spacer includes an elongatemember extending from a longitudinal side surface of the body portion;and a lateral spacer having a leading end and a trailing end and achannel configured to mate with the elongate member.
 2. The vertebralspacer system of claim 1, wherein the elongate member is a T-shapedcross section that extends a portion of the longitudinal side surface.3. The vertebral spacer system of claim 1, wherein the channel of thelateral spacer may include one or more rails.
 4. The vertebral spacersystem of claim 3, wherein the channel may terminate at a gap whichextends in a superior-inferior direction.
 5. The vertebral spacer systemof claim 3, wherein the channel includes a plurality of gaps.
 6. Thevertebral spacer system of claim 3, wherein the channel and rails mayincludes a series of interrupted channels and rails though whichelongate member of the body portions is configured to pass through. 7.The vertebral spacer system of claim 3, wherein the elongate member,channel and rails of the lateral spacer form a tongue and groove joint.8. The vertebral spacer system of claim 1, wherein the lateral spacerincludes a cavity for receiving bone graft.
 9. The vertebral spacersystem of claim 1, wherein the vertebral spacer and the lateral spacermay form a continuous angled and ramped surface.
 10. The vertebralspacer system of claim 1, wherein the vertebral spacer and the lateralspacer are ramped at different angles providing different degrees oflordosis.
 11. A vertebral spacer system, comprising: a vertebral spacerhaving a body portion, a first endplate, a second endplate, atranslation member, and an actuation member, wherein the translationmember and the actuation member cooperate to move the first and secondendplates away from one another, thereby increasing the height of thevertebral spacer; wherein the vertebral spacer includes an elongatemember extending from a longitudinal side surface of the body portion;and a lateral spacer having a leading end and a trailing end and achannel configured to mate with the elongate member wherein thevertebral spacer and the lateral spacer are secured between vertebralbodies by a plate system.
 12. The vertebral spacer system of claim 11,wherein the elongate member is a T-shaped cross section that extends aportion of the longitudinal side surface.
 13. The vertebral spacersystem of claim 11, wherein the channel of the lateral spacer mayinclude one or more rails.
 14. The vertebral spacer system of claim 11,wherein the plate system includes brackets, bone screws, and blockingscrews.
 15. The vertebral spacer system of claim 13, wherein the channelincludes a plurality of gaps.
 16. The vertebral spacer system of claim13, wherein the channel and rails may includes a series of interruptedchannels and rails though which elongate member of the body portions isconfigured to pass through.
 17. The vertebral spacer system of claim 13,wherein the elongate member, channel and rails of the lateral spacerform a tongue and groove joint.
 18. The vertebral spacer system of claim11, wherein the lateral spacer includes a cavity for receiving bonegraft.
 19. The vertebral spacer system of claim 11, wherein thevertebral spacer and the lateral spacer may form a continuous angled andramped surface.
 20. The vertebral spacer system of claim 11, wherein thevertebral spacer and the lateral spacer are ramped at different anglesproviding different degrees of lordosis.